AI Infrastructure Engineer
Mercor
About this role
ABOUT MERCOR
Mercor's mission is to organize human intelligence to power the AI economy. We're a leading AI data company, building the layer between human expertise and frontier models. Millions of domain experts on the platform are paid over $4 million per day to train frontier AI models. Mercor's APEX benchmark family measures AI's real-world impact on professional work. Mercor Enterprise brings this same infrastructure to Fortune 500 companies: helping companies capture how their best people actually work, translating that expertise directly back into agents.
Mercor is creating a new category of work where expertise powers AI advancement. Achieving this requires an ambitious, fast-paced and deeply committed team. You’ll work alongside researchers, operators, and AI companies at the forefront of shaping the systems that are redefining society. Mercor is a profitable Series C company valued at $10 billion. We work in-person five days a week in our San Francisco, NYC, or London offices.
Summary of role:
All of Mercor’s AI work, from training and serving models to building agents, runs on GPUs. Your job is to make that compute fast, fault-tolerant and fully utilized.
You’ll own the accelerator platform end to end. That means the clusters and schedulers across AWS, GCP, neoclouds and on-prem, the training and LLM serving on top, and the observability and cost data that show where every GPU-hour goes.
This is a software engineering role, not an ops role. You’ll write production code every day, own systems from design through on-call, and build the platform that sets how fast Mercor can move.
Representative projects
- Stand up a multi-cloud GPU fleet spanning hyperscalers, neoclouds and on-prem, orchestrated through custom Kubernetes and Slurm operators so researchers never have to think about where their job lands.
- Build a scheduling layer with gang scheduling, bin-packing and fair-share quotas that measurably raises accelerator utilization across teams.
- Ship a high-throughput vLLM serving stack with prefill/decode disaggregation, KV cache offload and FP8/FP4 quantization. Back it with a benchmarking and traffic-replay harness that tracks TTFT, TPOT and latency percentiles against per-config baselines.
- Build a self-healing health-check and remediation system that rides out fault storms across hardware, network and software without paging a human.
- Build an end-to-end cost-attribution pipeline. It ingests utilization, occupancy and billing data into the warehouse, attributes every GPU-hour to a team and workload, and drives capacity planning.
- Build internal tools and dashboards that researchers and non-engineers use every day.
Responsibilities:
- Design, deploy and operate GPU clusters across AWS, GCP, and other hyperscalers/neoclouds/on-premise data centers, including custom Kubernetes and Slurm operators and the metadata services behind them.
- Build scheduling that keeps accelerators busy: gang scheduling for distributed jobs, bin-packing to reduce fragmentation, and quotas and fair share for multi-tenant teams.
- Run distributed training infrastructure on PyTorch Distributed, Ray, or Megatron, with fast checkpointing and model loading.
- Deploy and tune high-throughput LLM serving with vLLM or similar: tensor and model/expert parallelism, prefill/decode disaggregation, KV cache offload, FP8/FP4 quantization.
- Build benchmarking and traffic-replay tools that measure TTFT, TPOT and latency percentiles, and set per-config performance baselines.
- Build health checks across hardware, network and software layers, and automated remediation that handles fault storms without human intervention.
- Instrument fleet utilization with DCGM, Prometheus and Grafana. Write recording rules and alerts that teams rely on.
- Ingest utilization, occupancy and billing data into a warehouse, attribute spend to teams and workloads, and support capacity planning.
- Drive autoscaling, rightsizing and idle-capacity recovery programs with measurable cost results.
- Write clear runbooks and documentation, and explain infrastructure tradeoffs to researchers, finance and leadership.
- Build internal tools or dashboards that researchers and non-engineers use daily.
You may be a good fit if you
- Have 5+ years building and operating production distributed systems or ML infrastructure
- Write production-quality Python plus Go or C++, and are fluent in shell scripting for system administration.
- Have deep hands-on Kubernetes and container experience, plus working knowledge of Slurm or another HPC resource manager.
- Have run GPU workloads at scale, including scheduling, orchestration and troubleshooting.
- Have hands-on experience with at least one distributed training or serving stack: PyTorch Distributed, Ray, vLLM or Megatron-LM.
- Have deep experience with at least one major cloud provider.
- Know observability tools like DataDog, Prometheus, PromQL and Grafana, and are comfortable on-call for critical systems.
- Own projects end to end and gather your own requirements with little direction.
Strong candidates may also have experience with (or a strong desire to learn deeply)
- LLM inference optimization: KV cache systems, disaggregated serving, quantization, speculative decoding
- High-performance networking: RDMA, InfiniBand, NCCL, NVLink
- GPU profiling with Nsight or similar, and CUDA or Triton kernel work
- Accelerators beyond NVIDIA: AMD MI-series, TPU, Trainium
- Capacity planning, billing normalization or cost attribution across providers
- Automated fault diagnosis, log mining or AIOps at fleet scale
- Configuration management (Ansible, Puppet) and secure or air-gapped deployments
Benefits
- Bi-annual performance bonus structure
- Generous equity grant vested over 4 years
- Up to $15k Relocation bonus
- $10K housing bonus (if you live within 0.5 miles of our office)
- $1.5K monthly stipend for meals
- Free Equinox membership
- $200 monthly laundry reimbursement
- $200 monthly personal wellness reimbursement
- Health, Dental, Vision insurance
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